Methods for the electro-chemical machining of a metallic structural component are known. The so-called electrochemical finishing for example represents a method for the exact and very precise machining of surfaces. During electrochemical finishing the surface of the work piece is usually machined with an electrode, whereby by means of electrochemical reaction of the work piece with the electrolyte that is located between the work piece and the electrode an ablation of material from the work piece is accomplished. In this case the electrode is connected to a direct current source as cathode. The electrode then moves toward the structural component that is biased as anode at a prescribed velocity. In the context of this so-called ECM (Electrochemical Machining) or PECM (Precise Electrochemical Machining)-method the width of the working space between the electrode and the structural component is of essential importance. During usual processes of the electrochemical finishing one works with spacings from the electrode to the work piece that are in the range of 0.1 to 1 mm. In order to generate finer structures and forms, the spacing can be lowered to dimensions on the order of 10 to 100 μm and lower. The successful application of a pulsed ECM-process (PECM) requires however in many application areas an even over-measure of the structural components to be machined. An electrochemically produced pre-contour of a blade of a gas turbine, particularly a Blisk (Blade Integrated Disks) blade, features for example a process-dependent over-measure between about 1 and about 3 mm. In order to achieve in these cases a necessary even over-measure the uneven over-measure has been machined up until now by means of milling. Such a method is however only useable to a very limited extent in the machining of very thin three-dimensional structural component profiles because the danger of damage, such as for example of a deformation of the structural components, exists in this case. In addition such a process step is relative effort-intensive and therefore costly.